The present invention relates to a walker to be used by the aged, and also relates to a baby walker. In particular, it relates to a structure that is foldable in two directions (i.e., the front/rear direction and the width direction), to a folding structure of a push rod section of the walker, and to an immobilizing mechanism which enables a user to easily manually halt the walker.
Recently, walkers of various types have been widely used as walking aids by aged persons who have weakened legs and limbs, replacing walking sticks or canes.
Thus, many kinds of walkers have been developed. For example, there are walkers with a seat portion so that the user may sit down on the seat portion anywhere at which the user becomes tired, and walkers with a storage space for storing goods after shopping. Many walkers also have a brake device for reducing the moving speed of the walker when, for example, going down a slope, and an immobilizing mechanism for inhibiting the movement of the walker.
It is desirable for the aged that the walker be capable of being stored in as small a space as possible, similar to a conventional baby cart. However, although the conventional walkers can be folded in the front-to-rear direction, many walker can not be folded in the widthwise (i.e., left-to-right) direction because of the comparatively large weight of the aged in comparison with the weight of a baby. As a result, a heavier structure is required to withstand weight of at least about 100 Kg. Furthermore, the requirement that the cart be foldable not only in the front-and-rear direction but also in the widthwise direction creates an undesirably complex mechanical construction and a heavy weight thereof.
The applicants of this application have filed a Japanese patent application relating to a handcart on Oct. 14, 1997, (Japanese Patent Application No. 9-280253).
According to the Japanese patent application, the handcart 15 is constructed, as shown in FIGS. 29 to 33, of a right and left pair of legs 1 and rear legs 2. A push rod 3 with an approximately U-letter shape has side portions which are mounted on the front legs, and the upper end portions of the push rod 3 are connected with each other. A right and left pair of seat rods 4 each have one end pivoted on a respective rear leg 2 and an intermediate portion pivoted on a respective front leg 1. A front connecting member 6 is composed of a pair of rigid members each including an outer end portion pivoted on the front leg, and each including an inner end portion rotatably supported around a pivot means 5. A rear leg connecting member 8 is composed of a pair of rigid members connecting the rear legs, and each of the pair include an outer end portion pivoted on the rear leg and an inner end portion rotatably supported around a pivot means 7. A pair of open/close rods 10 (FIG. 31) are arranged to have an approximately X-letter shape, and a lower end portion of each rod 10 is pivoted on one of the rear legs 2 and while upper end portion of each rod 10 is pivoted on the other rear leg 2 and the intermediate portions of each rod 10 is rotatably supported by a pivot means 9. A pair of operation rods 12 each have an outer end portion pivoted above the pivot means 9 on the open/close rods 10, and each have an inner end portion rotatably supported around a pivot means 11. A flexible connecting member 13 connects the pivot means 11 (which allows the inner end portion of each of the pair of operation rods 12 to pivot) and the pivot means 7 (which pivots on the inner end portion of the rear leg connecting member 8). Traction rods 14 each have lower end portions pivoted at a position adjacent to the pivot means 5 (rather than the center position) of each rigid member of the front leg connecting member 6, and each have upper end portions pivoted on one of the seat rods 4 at a position between two pivot means. Sliders 16 are provided for sliding the upper end portion of each rear leg with respect to each front leg when the walker is folded. (FIG. 30).
Furthermore, as shown in FIGS. 32 and 33, the push rod 3 is composed of a right and left pair of outer rods 17, a pair of inner rods 18 for sliding within the outer rods 17, a pair of rotation members 19 rotatable in the circular direction with respect to the upper end portion of each of the inner rods 18, a pair of handle portions 21 each having a lower end portion fixed on one of the rotation members 19 through a pin 20. Thus, the push rod 3 can be extended upwardly and then curved by about 90 degrees to form a pair of right-angle elbows. A connecting rod 22 extends upwardly from the upper horizontal portions of handle portion 21 to connect the horizontal portions. Moreover, the upper portion of each inner rod 18 is received in a respective rotation member 19, and the lower portion thereof is rotatably received in a respective outer rod 17. A plurality of holes 23 are provided on each outer rod 17 and each inner rod 18 with a constant gap. Thus, a vertical adjustment of the position of the handle portion 21 can be accomplished by inserting the pin into one of the holes 23.
Moreover, grooves 24 are formed on the rotation member 19, and the projected portion 25 mounted on the upper end portion of each inner end portion 18 is fitted in the groove 24. Thus, the rotation of the handle portions 21 around the inner rods 18 within a range of about 90 degrees can be achieved.
The hold member 26 for holding the inner end portion of each of the pair of operation rods 12 is moved upwardly. Furthermore, the pivot means 7 of the rear leg connecting members 8, 8 is moved upwardly through the connection member 13. As shown in FIG. 33 the horizontal portion of the pair of handle portions 21 is moved rearwardly by pulling the connection rod 22 rearwardly, and then the projected portion 25 moves in the groove 24 of each rotation member 19 outwardly from the position as shown in FIG. 32. By this, the walker 15 is compressed in the widthwise direction by the open/close rod 10 and simultaneously compressed in the front-to-rear direction by the front leg connecting members 6, 6 and the traction rods 14, 14. Thus, a position of being folded in the front-to-rear direction and the right-to-left direction is achieved.
By pushing the connection rod 22 forward, the horizontal portions of the pair of handle portions 21 are aligned on a straight line at the horizontal position, and the walker is expanded in the widthwise direction by expanding the open/close rod 10 to form an X-letter shaped formation. Furthermore, the walker is also expanded in the front-to-rear direction by the front leg connecting members 6,6 and the traction rods 14, 14 to achieve the expanded position as shown in FIGS. 29 and 31.
By this construction, there is presented a novel walker capable of supporting an adult in a stable manner, and also capable of being freely foldable in the front-to-rear direction and also the right-to-left direction safely and surely.
The connecting rod 22 is composed of two links A, B having recess portions as shown in FIG. 34, (JPA-1-297372). One end of each of the links A and B is connected to one of the handle portions through pins 27a, 27b, and the other end is connected to the other handle portion through the pins 28a, 28b sliding within the longitudinal slits mounted thereon. By operating the knob 29 contacting with the recess portion, two links A and B move thereby so as to enable the handle portion 21 to move from the straight state (FIG. 34A) to the folded state (FIG. 34B).
Moreover, a brake device, in which braking plates are depressed on the right and left rear wheels so as to brake the rear wheels, is generally known in the art. The brake plate is operated by a mechanism that is similar to the brake mechanism used in bicycles. Moreover, an immobilizing device having a push rod inserted from a side portion into projected portions which radially extend from and are integrally formed with the wheel at the periphery of the center hub of each of the right and left rear wheels is also known, and this device inhibits the rotation of the wheels. Moreover, a push rod operated from an outer radial direction of the wheel toward the center is also known, and the push rod contacts the projected portion extending in the radial direction at the periphery of the center of the rear wheel, thereby achieving the brake operation. The above-mentioned push rod may be operated by a foot by way of an operation rod for actuating the push rod, or it may be operated by a side lever.
The walker for the aged as mentioned above may be smoothly folded in the front-to-rear direction and in the widthwise direction. However, it is somewhat difficult to effectively prevent a shaking motion in the widthwise direction when the walker is open. The problem is caused by an insufficient rigidity in the widthwise direction when the walker is used in the opened condition. The object of the present invention is to present a walker having a novel structure for more effectively preventing the walker from shaking in the front-to-rear direction and in the widthwise direction when opened, in comparison with the conventional walker which can be folded in the front-to-rear direction and in the widthwise direction.
Moreover, in the conventional walker, the connecting rod 22 is composed of a pair of links with a complex structure. Furthermore, the links are rotated and moved along a straight line by utilizing pins and sliding grooves, thereby making the structure complex and expensive. The present invention, however, presents a connecting rod with a simple structure that is not expensive and can be folded rapidly.
Furthermore, in the conventional walker, the immobilizing device is heavy, thus increasing the overall weight of the walker. Furthermore, according to the walker having a foot pedal for actuating the immobilizing device, it is necessary to support both the user""s weight and the weight of the walker by using one leg of the user, and simultaneously depressing the foot-pedal by using the other leg of the user, thereby undesirably making the operation of the immobilizing device difficult. Furthermore, it has been difficult to combine the folding mechanism and the immobilizing device, resulting in a complex structure. Therefore, there has been danger that only one of the pair of immobilizing devices is effected, although it is necessary that left and right wheels be simultaneously stopped by the immobilizing device.
In order to solve the above-mentioned problems, the walker 30 of the present invention is provided with a tension reinforcement device for preventing shaking or distortion of the walker 30 in the front-to-rear direction and in the right-to-left direction as follows. The tension reinforcement device includes a first reinforcement device 57 composed of a first pair of traction rods 56 having lower end portions which pivot on the rigid member 40 at one side (right side or left side) of the front connecting member 41. The upper end portions of the first pair of traction rods 56 are pivoted on a position between the pivot means 36, 37 of the seat rod 38 of the other side (left side or right side). The first pair of traction rods 56 are arranged to form an X-letter shaped cross as is apparently shown in FIG. 3. A second reinforcement means 59 is composed of a second pair of traction rods 58 having lower end portions which are pivoted on a side (right side or left side) of the front leg 32 at a position adjacent to the front wheel 31. The upper end portions of the second pair of traction rods 58 are pivoted on a position between the pivot means 37 of seat rod 38 and the other end (front end) of seat rod 38. The second pair of traction rods 58 are disposed as forming an X-letter shaped cross as is apparently shown in FIG. 3.
Those reinforcement means 57 and 59 prevent the shaking or the distortion in the left and right direction of the walker 30.
This effect is very important when any shaking of the body of the walker should be avoided during moving thereof, as with a baby walker. However, in a walker for the aged in which small amount of shaking is allowable for the aged, one of the reinforcement devices may be omitted for avoiding any increase in the walker""s weight.
Moreover, the walking 30 of the present invention has a tension device 61 at both sides, and the tension device 61 is composed of a pair of tension rods 60 having first ends which pivot on the front legs 32 and the rear legs 34 at one side (right side or left side), respectively. The second ends of the tension rods 60 are rotatably connected with each other by using pins or the like. This achieves a very excellent function of avoiding any shaking or any distortion of the walker 30 in the front-to-rear direction.
Moreover, the push rod and the front legs of the walker of the present invention are formed with an integral member. Therefore, the distortion or shaking due to distortion of the walker 30 can be completely avoided.
Moreover, according to the present invention, the walker has at least a right and left pair of front legs, a right and left pair of rear legs, and a push rod. The push rod has vertical portions extending upwardly and has a lateral portion for connecting the upper ends of the vertical portions in the widthwise direction. The vertical portions each have a fixed portion at the lower side and a rotation portion rotatable with respect to the fixed portion at the upper side. The lateral portion for connecting the left and right rotation portions includes a coupling rod 67 pivotably attached at the intermediate portion through the connecting rod 92. In the walker which is foldable in the front-to-rear direction and the widthwise direction, the coupling rod 67 is composed of a pair of sliding bodies 102 and 103, a spring 121a for urging the sliding bodies such that the sliding bodies become adjacent to each other, an actuator 104 for actuating the sliding bodies such that the sliding bodies move apart from each other against the resilient force of the spring, and a knob 124 for operating the actuator. When the walker is in the opened condition, the sliding bodies are engaged through the connecting rod so as to maintain the lateral portion on a substantially straight line due to the resilient force of the spring. If the actuator is operated, the actuator renders the sliding bodies to be positioned apart from each other against the resilient force due to the spring so as to release the engagement, between the sliding bodies and the connecting rod and allow a free movement of the coupling rod 67 in a forward or backward direction.
According to the present invention, a single operation means 131, a plurality of immobilizing devices 133, and a force transmission means 134, 135 or 198 for coupling the operation mechanism 131 and the plural immobilizing devices 133. The operation means 131 has an operation lever 83 having a rotation portion 144 and an operation portion 145 for operating the rotation portion 144. The rotation portion 144 has a pivot means in opening 148 which can be pivoted on the walker 30 and a groove 146 and straight hole 147 for receiving one end of the force transmission means 134 and 198. The immobilizing device 133 has legs having a contact piece 188, and has a fixing means 194 for fixing the other end of the force transmission means 135 and 198. The legs are pivoted on the wheel supporting legs 34 and 34 supporting the wheels 33 and 33. The force transmission means 134, 135 and 198 maintain a predetermined gap between the operation means 131 and the immobilizing device 133, and transmit movement of the operation means 131 to the immobilizing device 133. Thus, the plural immobilizing devices 133 and 133 are simultaneously actuated by operating the singe operation means 131.